Recently, demand for mobile electronic devices, such as portable phones, notebooks, and digital cameras, is continuously increasing, and particularly, interest in flexible mobile electronic devices, to which scrollable displays, flexible electronic paper (e-paper), flexible liquid crystal displays (flexible-LCDs), flexible organic light-emitting diodes (OLEDs), and the like are applied, is increasing. Accordingly, a power supply device having a flexible property is also required for the flexible mobile electronic device.
A flexible battery has been developed as one of power supply devices having such a property. For example, a pouch-type battery, in which an electrolyte input and sealed in a pouch including two electrodes and a separator is used, has been developed.
Such a pouch-type battery has advantages in that the pouch-type battery can be manufactured in various shapes because of being made of flexible materials, and high energy density per mass can be achieved. However, when the pouch-type battery is excessively bent or twisted, an excessive load can be applied to an embedded electrode assembly. Thus, there is a problem in that the electrode assembly is broken and thus cannot serve as a battery due to such a load.
In addition, when the pouch-type battery is penetrated by a sharp tool, such as a needle or gimlet, or an edge of various objects, since there is no method to protect the pouch-type battery therefrom, there is a problem in that the electrode assembly embedded in the pouch-type battery is damaged and thus the pouch-type battery cannot perform functions thereof.